1. Field
One or more embodiments of the present invention relate to image correction, and more particularly, to a method, medium and apparatus correcting a projected image.
2. Description of the Related Art
A display system using a projector displays an image frame by projecting the image frame onto a flat screen. If the screen has a color of its own, the color of the image frame projected onto the screen is distorted compared with that of the actual image frame. In addition, if the screen is not perfectly flat, the projected image frame may have a geometric distortion due to the curvature or irregular surface of the screen.
In order to correct such distortion of the projected image frame, chromatic and geometric characteristics of the screen must be modeled. According to a conventional method of modeling characteristics of a screen, a predetermined pattern is projected onto the screen before an image frame is projected. Then, the projected pattern is photographed using a camera, and the projected pattern is compared with a photographed pattern. Based on the comparison result, a function indicating characteristics of the screen is obtained. Then, a reversed function of the function obtained is applied to the image frame that is to be projected onto the screen, thereby correcting the distortion of the image frame. Consequently, a user can view a corrected image frame.
There is a growing need for a technology to correct the distortion of an image frame caused by characteristics of a projection surface in order to project the image frame onto a projector screen or a projection surface such as a wall or a curtain.
However, since a pattern image for correction must be projected before an image frame is projected according to the conventional method, the correction process is cumbersome. Furthermore, the projection of the image frame must be delayed until the correction process is completed. Such inconvenience is aggravated in an environment where characteristics of a projection surface may vary according to the movement of the projection surface, or lighting changes.
Therefore, a technology for projecting an image frame while correcting the distortion of the image frame caused by characteristics of a projection surface, without user awareness, is needed.